This invention relates to vehicle transmission gearing and, more particularly, to an improved noise-reduction mounting for the reverse idler gear shaft of a vehicle manual transmission.
The prior art is replete with noise-suppressing gear arrangements. One example is found in U.S. Pat. No. 3,320,824 issued May 23, 1967 to P. H. Riley, Jr. et al. The Riley patent concerns a gear mounted on a splined shaft wherein tolerance accumulations may cause slight angular misalignments between the mating splines inducing vibratory noises during operation. Riley discloses noise-suppressing cushioning O-rings encircling the gear supporting shaft on either side of the gear. The O-rings are held under axial compression between the gear and a suitable retaining element such that the O-rings are deformed into firm engagement with a side face of the gear and with the shaft. The O-rings function to define a space to trap lubricant between the gear and the supporting shaft such that a film of lubricant is maintained to minimize metal-to-metal contact.
The U.S. Pat. No. 2,867,130 issued Jan. 6, 1959 to K. G. F. Moeller relates to reduction of gear noise such as devices attached to meshing gears for damping the noise produced when the gear teeth contact one another during operation. Moeller teaches using a pair of sound absorbing disks mounted on opposite sides of a gear in conjunction with an elastic ring located in a peripheral groove of the disks.
The U.S. Pat. No. 4,503,719 issued Mar. 12, 1985 to Hamano discloses a buffering mechanism for an automotive starter in which elastic members are provided in spaces defined between circumferentially opposed sides of depressions formed in the outer periphery of a ring gear of a planetary gear set and the inner periphery of a member receiving a reaction force.
The U.S. Pat. No. 3,854,349 issued Dec. 17, 1974 to Michling discloses a multi-stage speed reducer resilient shaft support. Michling discloses a speed reducer drive yieldingly mounting the output end of a central gear within the hollow shaft of a planet gear carrier of the output stage by means of resilient elements providing transverse limiting of movement. These elements are positioned and arranged such that upon removal of the load from the drive gear of the system, the resiliency or restoring force of the elements effect centering of the shaft journals of the central gear against the weight thereof.
The U.S. Pat. No. 3,408,830 issued Nov. 5, 1968 to A. Sutaruk et al discloses a torsion drive assembly wherein a rubber grommet has its inner periphery press fitted onto a torsion shaft sleeve. The rubber grommet functions as a dampener and aids in dampening the noise due to impact or shock loads imparted to the drive assembly as well as serving to maintain the sleeve concentric with the longitudinal axis of the torsion shaft. This maintains radial space therebetween and thus prevents rattling and fretting wear between the mating splines as the input member and the torsion sleeve.
The U.S. Pat. No. 2,460,630 issued Feb. 1, 1949 to T. L. Fawich discloses a multicushioned gear having cushioning means interposed between its toothed portion and its hub which engages the machine part on which the gear is mounted.